dawson and g



A.T;DAWSON AND G-T-BUCKHAM- mm smHTmG APPARATUS.

APPLICATION FILED APR.13| 1915- v I 1 ,306,409. Patented June 10,1919.

2 SHEETS-SHEET l.

A. T. DAWSON AND G. T. BUCKHAM.

GUN. SIVGHTING APPARATUS.

APPLICATION mzo APR. 13. 1915.

1,306,409. Patented June 10, 1919.

2 SHEETS-SHEET 2- co PNIJIO-LIYNO wAsmnoron, u g

UNITED STATES PATENT OFFICE.

ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUCKI-IAM, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNORS TO VICKERS LIMITED, OF WESTMINSTER,

ENGLAND.

GUN-SIGHTING- APPARATUS.

To all whom it may concern:

Be it known that we, Sir ARTHUR TREVOR DAWSON, knight, and GEORGE. THOMAS BUCK- HAM, both subjects of the King of England, and residing at Vickers House, Broadway, Westminster, in the county of London, England, have invented certain new and useful Improvements in and Relating to Grun- Sighting Apparatus; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to sighting apparatus for use with ordnance having an inde pendent lineof sight, in which means are employed for automatically deflecting the line of sight during the ranging of the gun to compensate for the error in line of fire resulting from the inclination of the gun trunnions to the horizontal when the gun carriage wheels are resting on uneven ground.

According to this invention the sight bracket is connected to one of the gun trunnions or to the carriage by means of a universal joint and is rotatably carried by a member slidably mounted upon a curved lateral guide formed on a pivotal arm or sight bar under the control of the pointing gear, the said sight bracket being connected to the gun cradle by a device which, after the sight bracket has been moved on the curved lateral guide of the sight bar about the universal joint into a vertical position, will automatically impart the correct deflection to the sight during the ranging operation. The sight bracket thus moves about the universal joint during the initial lateral adjustment of the sight to the vertical position, during the automatic deflection of the sight when the ranging operation is being performed, lL1 ?ing the-- relative.-. vertical mpmgmenttlgtttakes place between the gun and the bracket when ranging.

The pivotalarm or sight bar may in a modified form be so constructed and arranged that its point of connection with the pointing gear is situated at the side of the gun opposite to that at which the sight is disposed. For this purpose the sight bar may be in plan in the form of a triangular frame which is arranged above the gun cradle; its base, which is arranged transversely to the axis of the gun, has down- Specification of Letters Patent. Patented J 119 10, 1919 Application filed April 13, 1915. 4

Serial No. 21,118.

wardly extending arms pivoted concentrically with the trunnion axis. The apex of the frame may be suitably connected to the pointing gear which is preferably disposed near the breech end of the gun. In this manner we are not only enabled to place the sight at one side of the gun and the pointing gear at the other side as aforesaid, but a particularly rigid arrangement of sight bar is obtained which gives a wide and firm base thereby preventing any lateral movement of the sight bracket.

In order that the said invention may be clearly understood and readily carried into effect, we will describe the same more fully with reference to the accompanying drawings, in which:

Figures 1 and 2 are respectively a sectional side elevation and a sectional rear elevation showing a constructional form of the improved sighting apparatus, and Fig. 3 is a side elevation of a gun carriage (with one Wheel removed) showing the improved sighting apparatus thereon. Figs. 4, 5 and 6 are respectively a side elevation, a plan, and a rear elevation showing the triangular form of sight bar. Fig. 7 is a view similar to Fig. 3, showing the sight bar of Figs. 4, 5 and 6, and the sighting apparatus of Figs. 1 and 2 in position on the gun carriage; and Fig. 8 is a section on an enlarged scale, taken approximately on line 11 of Fig. 1.

A represents the sight bracket and A the member in which it is rotatably carried. 13 represents the pivotal arm or sight bar and B its curved lateral guide upon which the member A is slidably mounted.

In the example shown by Figs. 1 and 2, the sight bracket A is formed with a socket which receives a ball a (Fig. 2) mounted on projection a formed on or attached to one of the trunnions. The aforesaid curved lateral guide B is in the form of a bar on which slides the member A constituting a bearing for supporting the upper end of the sight bracket. The bar B has teeth with which engages a worm I) carried by the member A. The latter carries a spirit level 6 so that the correct amount of adjustment given to the bracket A by the worm Z) can be readily determined. The sight bar B is pivotally mounted upon one of the trunnions or upon a part of the trunnion band concentric with the trunnions. This bar is guided upon a rib B formed on the gun cradle or the trunnion band concentric with the gun trunnions and is connected at its rear end to a part moved by the pointing gear. It will be obvious that the gun c adle or trun- Ilion band might be formed with a dovetailed slot instead of a rib. The aforesaid device interposed between the sight bracket A, and the gun cradle comprises a slot A formed in the forward part of the sight bracket, this slot being concentric with the gun trunnions. Disposed in this slot is a block a? mounted on the gun cradle in a swiveling manner, so that it will accommodate itself to the different positions assumed by the slot A when the b 'acket A is adjusted as aforesaid by the worm b. The axis of rotation of this block is in a plane passing through the axis of the gun trunnions parallel to a plane passing through the axis of the gun. It will thus be seen that when the ranging movement of the gun takes place, the block a will move in the slot A If the sight bracket A has been previously adjust ed by the worm b as aforesaid, the slot A will lie in a plane which is not parallel with a plane containing the path of the axis of the gun during elevating movements of the latter. Consequently during the ranging movement the bracket A will, by the cooperation of the block (1, and the slot A receive a movement about a vertical axis to impart the correct deflection adjustment to the sight, the amount of this adjustment being dependent upon the degree of inclination of the gun trunnions and upon the range.

\Vhen the sight bracket is pivotally mounted on the carriage as aforesaid, suitable connections are provided to enable the sight to move with the gun during pointin The sight bracket may carry an open sight A and also a goniometric sight A the pivot of which is mounted in the bracket A.

In Figs. 4, 5, 6, and 7 the sight bar B is in the form of a frame of triangular formation in plan and its downwardly extending arms B 13 having trunnions B which are pivoted concentrically with the gun trunnion axis. The portion or apex 13* of the frame B is connected to the pointing gear.

The aforesaid curved lateral guide B (Figs. 1 and 2) is connected to the frame B by means of a dove-tailed or T-shaped key andkeyway arrangement B the key and keyway being preferably disposed in a vertical plane with the keyway (or it might be the key) formed on the outer face of one of the aforesaid downwardly extending arms B B of the frame. The key and keyway are preferably arranged immediately above the pivotal axis of the sight bar. The universal joint for the sight bracket comprises a sleeve Z2 and a pivot pin I) connecting the bracket to the sleeve. By the withdrawal of this pin the sight bracket is freed so that it, together with the sight carrier and the sight, can be removed from the gun, the aforesaid key and keyway arrangement permitting this operation to be readily effected. It will be seen that the apex B of the frame is on the opposite side to that occupied by the arm B" formed with the keyway and therefore opposite to that occupied by the sight. The other of the two arms B, B may be provided with a suitable level for indirect firing of the gun.

lVhat we claim and desire to secure by Letters Patent of the United States is 1. The combination with a gun, its trunnions, and the cradle, of sighting apparatus, comprising a sight bracket, a member moving with the gun during its pointing adj ustment, means for mounting the sight bracket on said member, means for adjusting the sight bracket on said member to bring the bracket to a vertical position and means interposed between said bracket and the gun cradle for automatically displacing the sight bracket to correct for drift during the ranging adjustment of the gun.

2. The combination with a gun, its trunnions, and the cradle, of sighting apparatus, comprising a sight bracket, a curved lateral member moving with the gun during its pointing adjustment, means for slidably mounting the sight bracket on said member, means for adjusting the sight bracket on said member to bring the bracket to a vertical position and means interposed between said bracket and the gun cradle for autonlatically displacing the sight bracket to correct for drift during the ranging adjustment of the gun.

3. The combination with a gun, its trunnions, and the cradle, of sighting apparatus, comprising a sight bracket, a curved lateral member moving with the gun during its pointing adjustment, a universal pivot for said bracket, means for slidably mounting the sight bracket on said member, means for adjusting the sight bracket on said member about the universal pivot to bring the bracket to a vertical position and means interposed between said bracket and the gun cradle for automatically displacing the sight bracket about its universal pivot to correct for drift during the ranging adjustment of the gun.

4. The combination with a gun, its trunnions, and the cradle, of sighting apparatus, comprising a sight bracket, a curved lateral member moving with the gun during its pointing adjustment, a universal pivot for connecting said bracket to the gun trunnion, means for slidably mounting the sight bracket on said member, means for adjusting the sight bracket on said member about the universal pivot to bring the bracket to a vertical position, and means interposed be tween said bracket and the gun cradle for automatically displacing the sight bracket about its universal pivot to correct for drift during the ranging adjustment of the gun.

5. The combination with a gun, its trunnions, and the cradle, of sighting apparatus, comprising a sight bracket, a curved lateral member moving with the gun during its pointing adjustment, a universal pivot for connecting said bracket to the gun trunnion, a bearing for the upper part of said sight bracket, means for slidably mounting said bearing on said member, means for adjusting the sight bracket on said member about the universal pivot to bring the bracket to a vertical position and means interposed between said bracket and the gun cradle for automatically displacing the sight bracket about its universal pivot to correct for drift during the ranging adjustment of the gun.

6. The combination with a gun, its trunnions, and the cradle, of sighting apparatus, comprising a sight bracket, a curved lateral member moving With the gun during its pointing adjustment, a universal pivot for connecting said bracket to the gun trunnion, a curved guide on the gun cradle for supporting said member, a bearing for the upper part of said sight bracket, means for slidably mounting said bearing on said member, means for adjusting the sight bracket on said member about the universal pivot to bring the bracket to a vertical position and means interposed between said bracket and the gun cradle for automatically displacing the sight bracket about its universal pivot to correct for drift during the rangin adjustment of the gun.

7. The combination with a gun, its trunnions, and the cradle, of sighting apparatus, comprising a sight bracket, a curved lateral member moving with the gun during its pointing adjustment, a universal pivot I for connecting said bracket to the gun trunnion, a curved guide on the gun cradle for supporting said member, a bearing for the upper part of said sight bracket, means for slidably mounting said bearing on said member, means for adjusting the sight bracket on said member about the universal pivot to bring the bracket to a vertical position, a spirit level carried by the sight bracket'and a cam slot device interposed between said bracket and the gun cradle for automatically displacing the sight bracket aboutits universal pivot to correct for drift difring the ranging adjustment of the gun.

8. In ordnance sighting apparatus having an independent line of sight, the combination of a universally pivoted sight bracket, a curved lateral member, means for slidably mounting the bracket on said member and a triangular frame which carries said lateral member and moves with the gun during its pointing adjustment, the base of this ame being arranged transversely to the gun and its apex situated at the side of the gun opposite to that at which the sight bracket is disposed.

9. In ordnance sighting apparatus having an independent line of sight, the combination of a universally pivoted sight bracket, a curved lateral member, means for slidably mounting said bracket on the lateral member, a triangular frame movable with the gun during its pointing adjustment, the base of this frame being arranged transversely to the gun and its apex being situated at the side of the gun opposite to that at which the sight bracket is disposed, and means for detachably connecting said lateral guide to the triangular frame.

10. In ordnance sighting apparatus having an independent line of sight, the combination of a universally pivoted sight bracket, a curved lateral member, means for slidably mounting said bracket on the lateral member, a triangular frame movable with the gun during its pointing adjustment, the base of this frame being arranged transversely to the gun and its apex being situated at the side of the gun opposite to that at which the sight bracket is disposed and a key and keyway connection between said lateral guide and the triangular frame.

In testimony whereof we aflix our signatures in the presence of two witnesses.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKHAM.

Witnesses:

HENRY KING, J NO. R. CAsEwELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

